When holders AC Milan stepped out for the second leg of their UEFA Champions League quarter-final against RC Deportivo La Coruña with a 4-1 lead, a place in the semi-finals looked a certainty.

'Mission impossible'Even Deportivo coach Javier Irureta admitted that becoming the first club in Champions League history to overturn a three-goal first-leg deficit was "mission impossible". But that is exactly what Deportivo did with a 4-0 home win that avoided the need even to rely on away goals.

Vital goalsSo where did it all go wrong for a Milan team who, if anything, looked a better side than they did a year ago? On the face of it, the answer is simple: Deportivo attacked from the off, Walter Pandiani scored quickly enough to unsettle the visitors, and Juan Carlos Valerón, Alberto Luque and Fran all produced goals at vital moments.

Surprise fragilityBut that does not explain how a team who had been beaten just once on their travels in 2003/04 and had not even conceded a goal away from home in this season's Champions League, should falter so spectacularly. The Rossoneri knew exactly what Deportivo were going to do - yet still proved so fragile.

Ancelotti shockedCoach Carlo Ancelotti's initial reaction was one of obvious shock. "It is difficult to explain," he said in a post-match interview with Italian television. "We were up against a very good team, who played very well and there were some errors on our part but it really is hard to explain this defeat. [Deportivo] were very determined and enthusiastic from the first to the last minute."

Deportivo rampantWhat made things worse for Ancelotti's side was that not only were they close to full strength, but that after going in at half-time 3-0 down and knowing they had to score in the second half, they were - if anything - penned back even more in the final 45 minutes.

'Simply destroyed'The Corriere dello Sport's anguished reaction sums up what a surprise that was. "While it was happening we could not believe it," the newspaper wrote. "We kept telling ourselves that sooner or later Milan would wake up." But Milan "were simply destroyed", the article admitted.

Maldini's explanationCaptain Paolo Maldini, a player with arguably more European experience than anyone in the Champions League, offered a possible explanation. "We tried to play rather than to defend our lead," he said. "We are not the sort of side who can play a closed game, but they produced a great performance and we were well below par. We conceded the early goal and then we could not hit them on the counterattack and we could not make the most of the chances we created in order to calm them down."

Crucial momentCertainly, the first half was not a completely one-sided affair. Jon Dahl Tomasson and Kaká had fine opportunities to score. It was only really after Valerón made it 2-0 on 35 minutes that Deportivo really began to dominate. Once they took control, though, Milan looked far from the side who stand just one win away from a new Serie A points record.

Superb performanceMilan proved susceptible to Deportivo's power and passion at the Riazor, but arguably there is no shame in that. After all, it may have been one of the greatest team performances in Champions League history. As Ancelotti said: "If Deportivo continue to play this way they will be worthy successors to Milan as European champions."

The CHAMPIONS LEAGUE and UEFA CHAMPIONS LEAGUE words, the UEFA Champions League logo and trophy and the UEFA Champions League Final logos are protected by trade marks and/or copyright of UEFA. No use for commercial purposes may be made of such trade marks. Use of UEFA.com signifies your agreement to the Terms and Conditions and Privacy Policy.